IE43020B1 - Improvements in or relating to valves for fluids - Google Patents

Abstract

1496283 Rotary valve engines DANA CORP 7 March 1975 [8 March 1974 13 Dec 1974] 9488/75 Heading F1B The subject matter of this Specification is the same as that of Specification 1496281 but the claims are directed to a rotary valve having an exhaust passage extending diametrally therethrough and a tubular heat shield co-extensive with the passage and in spaced relationship with the walls thereof.

Description

This invention relates to valves for rotary valve internal combustion engines.

In such engines, gases exhausted from the engine cylinder pass to an exhaust manifold through a passage in the valve which communicates the exhaust manifold and the engine cylinder in timed sequence with movement of the engine piston within the cylinder, and thus, in timed sequence with rotation of the engine crank shaft. In both the case of a two stroke engine having a valved exhaust, and in the case of a four stroke engine, it is required that the cylinder be connected with the exhaust manifold once during each complete engine cycle.

It is an object of this invention to provide a rotary valve for a rotary valve internal combustion engine, in which heating of the valve by the exhaust gases is minimized.

According to the present invention, there is provided a valve for a rotary valve internal combustion engine, the valve being of the type including a cylindrical valve body which is rotatable about its longitudinal axiswithin a cylinder head, and which is provided with at least one passage for communicating an engine cylinder with an exhaust manifold associated with the cylinder head, in which the passage extends through the valve and opens into the peripheral surface of the valve at diametrically opposed positions, and a tubular heat shield is positioned within said exhaust passage and extends through said passage in spaced relationship therewith. 43090 The Invention will be further described, by way of example, with reference to the accompanying drawings, in which:Fig. 1 is a cross section of a four-cylinder, fourstroke cycle engine; Fig. 2 is a perspective view of a rotary valve which is shown in cross section in Fig. 1; Fig. 3 is a perspective view of an embodiment of seals for the rotary valve shown in Figs. 1 and 2; Fig. 4 is a cross-sectional, end view of the seal shown in Fig. 3; Fig. 5 is a top view of the seal shown in Fig. 3; Fig. 6 is a detailed cross-sectional view of a timing apparatus of the engine shown in Fig. 1; Fig. 7 is another detailed cross-sectional view of the timing apparatus of the engine shown in Fig. 1; Fig. 8 and 9 are graphs of the operation of the timing apparatus of Figs. 6 and 7; Figs. 10 to 16 are cross-sectional views of the engine of Figs. 1 to 9 showing the relative position of the engine parts during a normal four-stroke cycle; Fig. 17 is a front end view of another embodiment of the engine; Fig. 18 is a perspective view of a cylindrical valve body shown in cross section in Fig. 17; Figs. 19 - 22 are partial sectional views of a further embodiment of stratified charge engine; Fig. 23 is an enlarged sectional view of timing apparatus of the engine shown in Fig. 17; Fig. 24 is a view similar to Fig. 23 showing another timing apparatus of the engine shown in Fig. 19; Fig. 25 and 26 are graphs of the operation of the timing apparatus of Figs. 23 and 24; - 3 4 3.0 3 9 Fig. 27 is a fragmentary perspective view of a four' cycle engine employing a non-stratified charge, and Fig. 28 is an exploded perspective view of the rotary valve and valve seals employed in the engine of Fig. 27.

Referring to Fig. 1, a four-cylinder, four-stroke cycle engine 10 is shown. It will, however, be clearly apparent that the invention finds equal utility in an engine operating as a two cycle engine, and, that the invention in no way is limited to engines having four cylinders.

The intermediate plate 21 defines, over each cylinder a dome 23 which forms an upper surface of a combustion chamber 24, defined on its remiani'ng sides by the cylinder walls 25 and the piston 14. A pre-combustion chamber 25 is also defined within the intermediate plate 21. The pre-combus tion chamber 26 is in direct communication, at the exit end, with the combustion chamber 24 and, at the entrance end, with valve passages which Will be described below. At the exit end of the- .pre-combustion chamber 26 is a restricting neck. 27, defined by the intermediate plate 21, which provides a restricted exit orifice for the ignited charge as will be explained below.

A spark plug 28 extends into the pre-combustion chamber through a bore 29 in the intermediate plate 21.

A valve head 30 is connected over the intermediate plate 21. The valve head 30 has an axial bore 31 in which is located a cylindrical rotary valve body 32, shown in greater detail in Fig. 2. A top side of the valve head defines sets of inlet ports I and exhaust ports E shown in detail in Fig. 2, over which an inlet duct 33 and an exhaust duct 34 (as shown in Fig. 1) is secured.

The valve body 32 comprises a light-weight frame 35, preferably of an aluminum alloy, caving an outer metal _ i) _ 43030 sleeve surfaced with a hard chrome plate fitted onto the outer periphery of the frame 35. The frame 35 can also be made of cast iron. The body 32 defines: (1) Inlet passages 36 which extend transversely through the valve body 32. The inlet passages 36 are arranged along the axis of the valve body 32 for registry with the inlet ports I in the valve head 30 at predetermined points of rotation of the valve body 32 within the axial bore 31. Registry of one of the inlet passages 36 with one of the inlet ports I also brings an opposite end of the inlet passages 36 into communication with the pre-combustion chamber 26, as will be explained below. (2) Exhaust passages 37 which also extend transversely through the valve body 32. The exhaust passages are arranged along the axis of the valve body 32 for registry with the exhaust ports E in the valve head 30 at predetermined points of rotation of the valve body within the valve head 30.

Registry of one of the exhaust passages 37 with one of the exhaust ports E also brings an opposite end of the exhaust passage 37 into communication with the pre-combustion chamber as will be explained below.

The inlet and exhaust passages 36 and 37 are disposed within the valve body 32 so that rotation of the valve body 32 produces sequential registry of one inlet passage 36 with one inlet port I and then one exhaust passage with one exhaust port E per four-stroke cycle of each piston 14 as will be further explained. (3) Cooling passages 38 (Fig. 1) which extend axially through the valve body 32 for transportion of cooling water therethrough. The combination of axial flow cooling and light alloy metal of the valve body 32 provides efficient cooling of the body 32 and especially the walls of the inlet and exhaust passages 36 and 37. _ .5 <3 3 Ο 21© The valve body 32 is carried on journals 39 for rotation within the axial bore 31 by bearings 40 which are connected to the valve head 30. The valve body 32 and the axial bore 31 are sized for close registry therebetween to facilitate sealing of the valve.

A gear G is connected through a chain or gear belt (not shown) to the crankshaft 13 for rotation of the valve body 32 in timed relationship with the crankshaft 13 at a ratio of 1:4. All rotation of the valve body, as discussed hereinafter is, therefore, in relation to the movement of the piston 14 within one of the cylinders 12 during a phase of a normal four-stroke cycle. Rotation of the valve body 32 shown in the drawings is in a clockwise direction (see Fig. 1).

Referring now especially to Fig. 1, the inlet duct 33 is connected for communication with each inlet port I in the valve head 30. The inlet duct 33 comprises a first passage L and a second passage R which extend from separate throats of, for example, a twin throated carburetor C to the valve body 32. A dividing wall 41 extends the length of the duct 33 to a point of sliding contact with the valve body 32 and, in conjunction with outer walls of the duct 33, defines the passages L and R. The first passage L transmits an extremely lean fuel/air charge, or a pure air charge, from the carburetor to the inlet I. It has been found in practice that the engines of Fig. 1 operates most efficiently with a charge of pure air delivered from the carburetor through the first passage L. Depending on engine capacity and design demand characteristics, however, it may be necessary to inject a lean mixture of fuel and air into the first passage L.

The second passage R transmits an extremely rich fuel/air charge, from the carburetor to the inlet I. It has been found in practice that the engine of Fig. 1 operates most 43030 efficiently with a fuel charge in passage R of maximum fuel/air ratio. Design characteristics may again require the modification of this charge to a rich fuel/air charge depending on engine construction.

It can be seen that as the inlet passage 36 rotates into registry with an inlet port I and the pre-combustion chamber 26, the passage 36 moves into sequential communication first with passage L, then with both passages L and R, and finally exclusively with passage R as a trailing wall of the inlet passage 36 passes the dividing wall 41.

As one end of the inlet passage 36 moves in the above-described sequential registry with the inlet duct 33, the opposite end of the passage 36 moves into registry with the pre-combustion chamber 26. Thus, as the piston 14 moves on its downward intake stroke, the inlet passage 36, rotating in time with the linear movement of the piston, introduces first a lean or pure air charge, then a mixed but lean fuel/air charge and finally a rich fuel/air charge through the pre-combustion chamber into the cylinder. When the intake stroke is completed, the inlet passage 36, in cooperation with the bifurcated inlet duct 33, has provided a very lean charge to the combustion chamber 24 and a rich charge to the pre-combustion chamber 26.

Referring now in particular to Figs. 2-5, a gasket and seal assembly 42 is situated at the base of the rotary valve head. The gasket and seal assembly 42 comprises a diaphragm gasket 43 made of a resilient, heat resistant metal such as stainless steel. The diaphragm gasket 43 is complementary in shape and size to the valve head 30 and is positioned between the head 30 and the intermediate plate 21 to prevent leakage of gases under pressure between the intermediate plate 21 and the valve head 30.

Valve seals 44 are mounted within apertures in the diaphragm gasket 43. Each seal is secured within the associated - 7 4 3 0 3 0 opening and is positioned for registry with an inlet and an exhaust passage 36 and 37 of the rotary valve to establish open communication between the passages 36 and 37 and the associated cylinder 12 of the engine 10.

An arcuate side 45 of each seal 44 is shaped for a contiguous fit with the rotary valve body 32. The resilient diaphragm gasket 43 is biased toward the valve body 32 to maintain the valve seals 44 in a contiguous sealing relationship with the outer wall of the valve body 32.

As shown in Fig. 1, the Valve seals 44 alternatively may comprise molded carbon rings which are positioned within a retaiher shoe S which is inserted into each opening within the diaphragm 43.

The provision of an arcuate carbon seal 44 has been found to be particularly advantageous because of the tendency of carbon to retain water against the arcuate surface 45.

The seal 44 can therefore be lubricated by water given off during the combustion process within the combustion chambers and 26.

The seals 44 can also comprise sintered iron or bronze which is molded into the seal shape. The sintered metal seals are provided with a capillary oil lubricating feed system as shown in Figs. 3, 4 and 5, comprising an oil feed line 47 leading from the engine lubrication system to an oil duct 48 which is molded circumferentially within the sintered iron or bronze seal 44.

In this embodiment of the valve seal 44, an inner stratum 49 and the arcuate surface 45 of the seal 44 are porous while an outer seal side wall 50 is non-porous and impervious to lubricating oil flow therethrough. After oil under pressure is fed through the oil feed line 47 to the oil duct 48, the oil percolates from the duct through the porous inner stratum to _ 8 _ 43030 the arcuate surface 45 which becomes saturated with the lubricant. The valve body 32, in contact with the lubricant, thus slides in lubricated contact with the arcuate sealing surface 45. The provision of either a carbon seal or a sintered metal seal against the rotary valve body 32 inhibits the exit of gases under pressure either between the intermediate plate 21 and the valve head 30 or around the rotary valve body 32. Typical problems with burning and erosion of the valve body 32 are greatly reduced by the seal.

Referring to Fig. 4, the diaphragm gasket 43 is provided with a corrugated lip 43a which extends around the circumference of each seal receiving opening, and which is positioned within a notch 44a extending around the seal 44.

The lip 43a extends within the notch 44a for retaining the seal 44 in place within the gasket 43. It can be seen in Fig. 4, that the lip 43a extends substantially but not completely the depth of the notch 44a to permit the seal 44 to float within the supporting gasket 43. The float permits the seal 44 to grow or shrink in respense to engine temperature variations at a rate different from the growth or shrinkage of the dissimilar material of the diaphragm gasket 43. The seal is thereby carried in contact with the valve body 32 without being placed under heat stress which would otherwise occur during operation of the engine.

As shown in Fig. 4, the lip 43a can, in cross section, comprise a down-turned bend (as shown at the left-hand side of Fig. 4) or as an S shaped curve, as shown at the right-hand side of Fig. 4. Either of these shapes facilitates gas loading of the lip 43a area within the notch 44a. Thus in the event that gas under pressure in the chambers 24 and 26 bleeds into the notch 44a, the gas will exert a force on the inside curves of either of the corrugated lips 43a to expand the corrugations into tight engagement against sidewalls of the notch 44a within the seal 44.

The diaphragm gasket seal 42 thereby provides a means for - 9 4308« sealing the rotary valve body 32 and for maintaining the seal against failure through heat stresses encountered within the engine under operating conditions.

Referring especially to Fig. 7, an exhaust passage 37 within the valve body 32 is shown in cross-section. The exhaust passage 37 is protected from high temperature exhaust gases which pass therethrough during an exhaust stroke of the piston by a liner 51 formed of a heat resistant alloy, such as stainless steel, which extends across each wall of the exhaust passages 37.

Opposite ends of the inner liner 51 are bent outwardly and register with a sleeve extending around the valve body 32.

The bends act as spacers to maintain the linear 51 spaced from each wall of the exhaust passage 37 to provide a dead air space 52 between the adjacent wall of the exhaust passage 37 and the liner 51. The dead air space 52 provides an insulating layer shielding the valve body from exiting hot exhaust gases.

The hot, high pressure gases released from cylinder 12 on the exhaust cycle flow over the surface of the liner 51 and will maintain the liner at a red-hot temperature. In the event that a catalytic converter or thermal reactor is used in treating the exhaust of the engine, the red-hot temperature of the liner is advantageous in that a high exit temperature of the exhaust gases is maintained, which promotes the treating of those gases by the catalytic converter or thermal reactor.

Referring now to Figs. 10-16, the operation of the engine 10 through a complete four-stroke cycle is shown. When the piston 14 has travelled approximately half the distance toward bottom dead center in its intake stroke as shown in Fig. 10, the valve body 32 has carried the inlet passage 36 into open registry with both inlet ducts L and R as explained above.

As the piston 14 reaches bottom dead center, as shown in Fig. 11, the inlet passage 36 has rotated sufficiently far that the trailing wall of the passage 36 has passed the dividing wall 41, placing the pre-combustion chamber in communication exclusively with the inlet duct R.

As the comoression stroke begins, the inlet passage 36 is rotated beyond the point of registry with the pre-combustion chamber as shown in Fig. 12, thus closing the inlet passage 36 from communication with the pre-combustion chamber 26.

With the valve body 32 still rotating and the inlet passage 36 in a closed condition, the compression stroke of piston 14 is complete, as is shown in Fig. 13. Upon completion of the compression stroke, the relatively lean fuel/air charge in the primary combustion chamber 24 is in a stratified layer below an extremely rich charge compressed in the pre-combustion chamber 26.

Ignition takes place in the pre-combustion chamber as the spark plug ignites the very rich mixture therein. A flame front propagates out through the neck 27 into the combustion chamber 24 and ignites the lean mixture therein. The flame front propagates in the lean mixture at a uniform rate throughout the power stroke.

In a conventional engine, the gas temperature increases at a rapid rate to reach a high peak followed by a rapid fall-off within a short duration of movement of the crank toward bottom dead center. This short duration/high peak gas temperature first provides a short time during which minimum hydrocarbon combustion temperatures are maintained and second achieves a high enough point to form oxides of nitrogen.

The temperature curve of the slowly propagating flame produced in the stratified charge, however, provides a long-duration burn above minimum hydrocarbon combustion temperature and at the same time, achieves a peak temperature which is. below that required to produce oxides of nitrogen. 43QS0 As compared with a conventional engine therefore, the production of HC and NO pollutants during the power stroke is significantly - if not completely - eliminated in the stratified charge engine.

As the piston 14 makes its power stroke as shown in Fig. 14, the valve body 32 rotates the exhaust passage 37 into registry with the exhaust port E and the pre-combustion chamber 26. After the piston reaches bottom dead center, shown in Fig. 15, the exhaust stroke commences as shown in Fig. 16. Exhaust gases are driven from the combustion chambers 24 and 26 over the liner 51 and into the exhaust duct 34. The crankshaft 13 continues to rotate the valve body 32 in timed relationship and carries the piston 14 again to top dead center where the intake stroke again commences.

It can be seen that when the intake stroke is completed and the inlet passage 36 is closed, a portion of the extremely rich charge from inlet duct R is trapped in the inlet passage 36. When the inlet passage 36 is again brought into registry with inlet duct L· and the pre-combustion chamber 26, the trapped rich charge therein is drawn into the cylinder as the intake stroke commences. In this manner, even with pure air being supplied to inlet duct L a very lean fuel/ air charge is immediately introduced in the cylinder 12 when the inlet passage first moves into registry with the precombustion chamber 26.

Now refering to Figs. 6-9, an apparatus for varying the timing of the inlet and exhaust passages 36 and 37 is shown. Arcuate slide seals 53 are positioned within oppositely extending arcuate channels 54 on opposite sides of each inlet port I and exhaust port E. The slide seals 53 are fitted for 43030 complementary, contiguous registry with the valve body 32 and form upper seals for the body 32 adjacent the inlet and exhaust ports I and E. The slide seals 53 are, furthermore, extendable from a retracted position within the channel 54 to a restricting position within the path of the inlet or exhaust ports I or E as indicated by the dashed lines of Figs. 6 and 7.

As shown in Fig. 6, the slide seals 53 are movable by means of an actuating mechanism 55 which can comprise any suitable apparatus for moving the seals 53 in response to engine demand. For example, the actuating means 55 can be connected for vacuum operation to move timing rods 56 which are connected to the seals 53. The seals 53 are biased away from their restricting position by bias springs 57 connected to the timing rods 56. An increase in vacuum within the actuating mechanism 55 moves the seals 53 toward their restricting position. Therefore, connection of the actuating mechanism 55 to a port downstream of a throttle plate (not shown), for example, will cause the seals to be urged to their restricting position during engine idle conditions (a high vacuum condition) and toward their retracted position during open throttle conditions (a low vacuum condition).

To accomplish timing of the registry of an inlet passage 36 with an inlet port I, the slide seals 53 are moved in response to engine demand as described above, Thus when the engine is in an idle condition, the slide seals 53 extend from the opposing channels 54 into the restricting position as shown in dotted lines in Fig. 6. Movement of the lefthand seal, as viewed in Fig. 6, causes the intake passage 36 to communicate with the inlet port I later than when the seal - 13 _ 0 30 is in its retracted position. Movement of the right-hand seal 53 into the restricting position causes the inlet passage 36 to break communication with the inlet port I relatively sooner.

Similarly, movement of the left-hand seal 53, to the position shown in dotted lines in Fig. 7, causes the exhaust passage 37 to communicate with the exhaust port E later than when the seal 53 is in its retracted position. Likewise, movement of the right-hand seal 53 into the restricting position causes the exhaust passage 37 to break communication with the exhaust port E relatively sooner.

The provision of variable timing in response to engine demand is significant because in modern .engine design it is usual to effect the opening of the inlet valve before the piston reaches the top of the exhaust stroke. The valving is timed so that the exhaust valve closes after the inlet has opened so that there is overlap - a predetermined period when both valves are open together. This valve overlap is provided to produce maximum power during wide open throttle or high demand periods of engine operation.

In the high demand condition, high velocity escaping exhaust gases during an exhaust stroke, create a near-atmospheric pressure (or a slightly negative pressure) within the exhaust port. At the same time, a charge in the induction column is under a positive pressure.

When the inlet valve opens on the exhaust stroke, therefore, the positive pressure charge in the induction manifold sweeps into the cylinder and forces remaining combusted gases out through the open exhaust valve. The scavenging effect of the new charge pushing out the old _ 1A43020 assures that a maximum amount of new charge is drawn into the engine.

Furthermore, in order to assure that a maximum amount of new charge is introduced into the cylinder, the inlet valve is commonly closed at a point after the piston reaches the bottom of the intake stroke. During high demand, the positive pressure of the charge within the induction manifold maintains a positive flow into the cylinder even though the piston has begun its upward travel on the compression stroke.

It is also common practice to cause the exhaust valve to open at a point before the piston reaches the bottom of the power stroke in order to assure that the exhaust valve is completely open throughout the exhaust Stroke. During periods of high demand, the piston speed, as well as the highly efficient combustion environment of the cylinder, assures that relatively few unburned hydrocarbons or raw fuel escape through the exhaust passage.

This above-described valve timing provides a relatively ideal combustion environment within the cylinder during periods of engine demand. Therefore, a conventionally timed valving system in an automotive engine has a cycle similar to that illustrated in Fig. 8. In that cycle, the intake valve opens at approximately 22° of crank angle before top dead center and closes at 66° after bottom center. The exhaust opens at 65° before bottom center and closes at 24° after top center.

Under idle conditions, however, the above-described timing becomes detrimental to engine operation. During idle, there is a high degree of vacuum in the intake tract. When - 15 the piston reaches the top of its travel during the exhaust stroke, the pressure of the gases inside the cylinders is considerably above that of atmosphere, while inside the induction manifold it is a good deal below that of atmospheric Therefore, at the moment of opening the inlet valve, there is a pronounced difference of pressure across the valve orifice which causes some of the exhaust gases to be drawn into the intake manifold. When the piston begins to move down on the intake stroke, a portion of the inspired charge will consist of exhaust gases, thus reducing combustion efficiency within the cylinder.

Furthermore, because the exhaust valve typically opens prior to the completion of the power stroke the charge within the cylinder begins to exhaust before combustion in the relatively poor environment is complete. This results in the emission of unburned hydrocarbons and even raw fuel into the exhaust manifold, increasing the fuel consumption of the engine and the output of undesirable emissions.

The provision of the adjustable slide seals 53, however, provides for variation in the timing of the inlet and exhaust passages 36 and 37 to smooth out engine idle operation and reduce fuel consumption and emission output.

Thus as the opposing seals 53 are moved to the restricting position during engine idle, both ports 36 and 37 are caused to open late (due to the restriction caused by the right-hand seal 53) at top dead center and to close early (due to the restriction caused by the left-hand seal 53) at bottom dead center, as is depicted in the graph of Fig. 9.

As a result of the movement of the seals 53 into their restricting position, (1) valve overlap is virtually 1643020 eliminated during idle and (2) the exhaust passage 37 does not move into registry with the exhaust port E until the piston reaches virtually bottom dead center. The elimination of both valve overlap and the early opening of the exhaust port in response to a reduction in engine demand assures that combustion gases will not be introduced into the inlet ducts L and R on the exhaust stroke and also assures that complete combustion takes place in the combustion chamber 24 prior to the opening of the exhaust passage 37. Engine idle speed can therefore be reduced without the conventional attendant rough running, high fuel consumption and high pollution output.

Referring to Fig. 17, a stratified charge engine 110 is shown which includes a crank shaft 111, a connecting rod 112, and a piston 113 mounted for reciprocation within a cylinder 114 within an engine block 115. The engine may be of any configuration such as, for example, an in-line 4-cylinder engine having a conventional oil lubrication system 116, electrical system and fly wheel, as are well known in the engine art.

The engine 110 includes a cylinder head 117, connected to the block 115 over the cylinder 114. The cylinder head 117, the cylinder 114 and an upper working surface of each piston 113 define a main combustion chamber 118 within each cylinder 114.

The cylinder head 117 includes an elongate horizontal bore 119 having a rotatable cylindrical valve body 120 mounted in close registry within the bore 119. The valve body 120 is driven by a belt (not shown) through a driving gear G (see Fig. 18) which is operatively connected to the crankshaft 111. The ratio of revolutions of the crankshaft - 17 4303® 111 to those of the valve body is 4:1.

The valve body 120 comprises a cast iron or light alloy frame having a hardened cylindrical outer surface 121. Diametrically extending first and second inlet passages 122 and 123 and diametrically extending exhaust passages 124 are spaced apart axially along the cylindrical valve body 120 and are located for registry with separate intake and exhaust ducts as will be discussed below.

Referring to a single cylinder, the first inlet passage 122 is located axially within the valve body 120 for registry with a first intake manifold L for transmitting the lean fuel/air charge from a first metering device (such as a first venturi within a carburetor 126) to the combustion chamber 118. Rotation of the valve body 120, brings the inlet passage 122 into simultaneous registry between the inlet duct L and the main combustion chamber 118.

As the piston 113 descends On its inlet-stroke the lean fuel/air charge is drawn through the inlet duct L into the combustion chamber 118.

Referring particularly to Figs. 17 and -23, a second inlet passage 123 is spaced axially from the first passaqe 122 and is aligned for registry with a second inlet duct R for transmitting the rich fuel/air charge from a second metering device, to a pre-combustion chamber 128.

The second inlet passage 123, upon timed rotation of the valve body 120, is aligned for simultaneous registry with the inlet duct R and with the pre-combustion chamber 128, which is defined by the head and extends into open _ 43030 communication with the combustion chamber 118. A spark plug 129 extends into the pre-combustion chamber 128.

The inlet ducts L and R enter in open registry with the valve body 20 at points approximately 90 degrees apart.

At the same time, the inlet passages 122 and 123 extend diametrically through the valve body at 90 degree angles to one another. The two inlet ports 122 and 123 are therefore situated within the valve body 120 for approximately simultaneous registry of the inlet duct L with the combustion chamber 118 and of the inlet duct R with the pre-combustion chamber 128. Furthermore, the perpendicular relationship of the inlet passages 122 and 123 assures a completely symmetrical timing of the opening and closing of the passages 122 and 123 as they move in and out of registry with their respective inlet ducts 1, and R through two complete four-stroke cycles of the engine which effects one complete rotation of the rotary valve body 120.

The timing of these intake passages will be discussed below.

Upon a timed rotation of the valve body 120 in conjunction with a down-stroke of the piston 113 on an inlet stroke, the combustion chamber 118 is supplied with a lean fuel/air mixture and simultaneously the pre-combustion chamber 128 is supplied with a rich fuel/air mixture. Further rotation of the valve body 120 brings the inlet passages 122 and 123 out of registry with the respective combustion chambers 118 and 128 as the piston 113 commences its compression stroke as will be discussed below.

Referring now to Figs. 19-22, a third embodiment of the stratified charge engine of the present invention is shown.

In this embodiment, and again referring to a single cylinder, a first rotatable valve body 230 includes first and second inlet passages 232 and 231 for respective registry with an inlet duct L and a combustion chamber 218, and an inlet duct R and a pre19ό§03© combustion chamber 228. The pre-combustion chamber 228 is in communication with the combustion chamber 218 through an orifice located adjacent the axis of the piston 213. The inlet passage 232 establishes communication between the inlet duct L, and the combustion chamber 218, at a point near the outer circumference of the cylinder 214 within the head 217. Upon the intake stroke of the piston 213 the respective inlet passages 231 and 232 rotate into approximately simultaneous registry with the respective combustion chambers 228 and 218 for supplying a lean charge to the combustion chamber 218 and a rich charge to the pre-combustion chamber 228 as discussed above in the description of the single-valved embodiment of the invention, A second valve body 233 within the cylinder head 217 includes ah exhaust passage 234, and is driven in timed rotatation by the crankshaft 211 through a timing chain (not shown).

As will be explained below, the exhaust passage 234 is rotated into communication with the combustion chamber 218 and an exhaust duct E upon an exhaust Stroke of the piston 213.

The operation of the single- valved embodiment illustrated in Figs. 17 and 18 and that of the dual-valved embodiment illustrated in Figs. 19-22 is similar. It has been found, however, that the dual-valved embodiment is preferred for the reasons that the valve bodies 230 and 233 may be of smaller diameter than that of the single valve bodied engine shown in Fig. 17 and because the pre-combustion chamber 228 can be readily located adjacent the axis of the piston 213 for optimum flame propagation into the main combustion chamber.

Since the operation of the engine of each embodiment is substantially similar, the following discussion of the operation of the engine as illustrated in Figs. 19-22 will also substantially apply to the operation of the single valve bodied engine as shown in Fig. 17.

In operation, the inlet and exhaust valve bodies 230 and 233 rotate in relation to the crankshaft at a ratio of 1 revolution of the valve bodies 230 and 233 for every 4 revolutions _ 43030 of the crankshaft. The valve bodies rotate in a clockwise direction as viewed in Figs. 19-22. Therefore, for every single stroke of the piston 213 the valve bodies 230 and 233 rotate one eight of a turn or 45 degrees about their axes. Therefore, in a 4-stroke cycle, the engine operates as follows: As the piston reaches top dead center following an exhaust stroke as illustrated in Fig. 19, the exhaust passage 234 remains in partial registry with the combustion chamber 218 and the exhaust duct E. At the same time, the first and second inlet passages 231 and 232 have moved partially into communcation with their respective combustion chambers 228 and 218, with both the exhaust passage 234 and the inlet passages 231 and 232 thus in registry with the combustion chambers, optimum scavenging of the chambers 218 and 228 is effected. The amount of this valve overlap is optimumly determined by various engine design characteristics and demands which are conventionally known in the art.

As the piston 213 moves towards bottom dead center as shown in Fig. 20, the exhaust passage 234 is rotated out of registry with the main combustion chamber 218, thus closing the exhaust valve body. At the same time, the inlet passages 231 and 232 rotate into maximum open registry with the precombustion chamber 228 and the main combustion chamber 218 respectively. A rich charge is thus drawn through the inlet duct R and the inlet passage 231 into the pre-combustion chamber 228. At the same time, a lean charge is drawn through the inlet duct L and the second inlet passage 232 into the combustion chamber 218.

As the piston 213 reaches bottom dead center on the intake stroke (or slightly passes bottom dead center, depending _ upon the desired valve timing as will be discussed below), the first inlet valve body 230 has rotated 45 degrees carrying the inlet passages 231 and 232 out of registry with the combustion chambers 218 and 228 and out of registry with the inlet ducts L and R. The inlet valve is thus closed to provide for the compression stroke of the engine.

As the piston approaches top dead center, as shown in Fig. 21, the spark plug 229 is energized through a conventional coil and distributor electrical system to ignite the rich mixture trapped in the pre-combustion chamber 228. As the mixture ignites, a flame propagates from the pre-combustion chamber into the lean mixture in the primary combustion chamber to effect a long, and relatively uniform burn of the fuel charge as the piston 213 commences its downward power stroke.

As the piston 213 commences its ascending exhaust stroke, the exhaust passage 234 once again begins to rotate into registry with the combustion chamber 218 to effect discharge of the burned combustion gases from the combustion chamber 218.

As the piston 213 approaches top dead center, the inlet passages 231 and 232 again begin to rotate into communication with the combustion chambers 218 and 228 to effect valve overlap to enhance the scavenging effect as discussed above. The engine subsequently repeats the 4 strokes of the conventional 4-stroke cycle.

Referring now to Fig. 17 the valve body 120 is shown as being in sliding engagement with elongate seals 135 comprised of sealing material such as compressed carbon or the like. End seals (not shown) also are provided of a configuration complementary to the circumferential end surface of the valve body 120. The seals 135 are positioned within <13020 notches machined in the head 117 adjacent openings into the elongate bore 119 for registry with the two inlet passages 122 and 123 and the exhaust passage 124. The seals 135 are biased against the outer surface of the valve body 120 by spring strips (not shown) which are sandwiched between the seals 135 and the bottommost portion of each notch within the head 117. The spring strips preferably comprise a resilient undulating stainless steel member for urging the seals 135 into sliding relationship with the valve body 120.

Referring now to Figs. 23-26, an apparatus for varying the timing of the inlet passage 122 and the exhaust passage 124 is shown. Arcuate slide seals 138 are within oppositely extending arcuate channels 139 on opposite sides of the inlet duct L and the exhaust duct E. The slide seals 138 are fitted for complementary, contiguous registry with the valve body 120 and form upper seals for the body adjacent the respective inlet and exhaust ducts L and E. The slide seals 138 are extensible from a retracted position within the channel 139 to a restricting position within the path of the inlet or exhaust ducts L and E, as indicated by the dashed lines of Figs. 23 and 24.

The slide seals 138 are movable by means of an actuating mechanism 140 which can comprise any suitable apparatus for moving the seals 138 in response to engine demand. For example, the actuating mechanism 140 can be connected for vacuum operation to move sets of timing rods 141 which are connected to the seals 138. The seals 138 are biased away from their restricting position by bias springs 142 connected to the timing rods 141. An increase in vacuum within the actuating mechanism 140 moves the seals 153 toward their restricting position. Therefore connection of the actuating mechanism 140 to a port downstream of a throttle plate (not shown), for <3 30-2® example, will cause the seals to be urged to their restricting position during engine idle conditions (a high vacuum condition) and toward their retracted position during open throttle conditions (a low vacuum condition).

To accomplish timing of the registry of .the lean inlet passage 122 with the inlet duct L, the slide seals 138 are moved in response to engine demand as described above.

Thus when the engine is in an idle condition, the slide seals 138 extend from the opposing channels 139 into the restricting position as shown in the dashed lines of Fig. 23. Movement of the left-hand seal, as viewed in Fig. 23, causes the inlet passage 122 to move into registry with the inlet duct L later than when the seal 138 is in its retracted position. Movement of the right-hand seal 138 into the restricting position causes the intake passage 122 to move out of registry with the inlet duct L relatively sooner.

Similarly, movement of the left-hand seal 138, as viewed in Fig. 24, causes the exhaust passage 124 to move into registry with an exhaust duct E later than when the seal 138 is in its retracted position. Likewise, movement of the right-hand seal 138 into the restricting position causes the exhaust passage. 124 to move out of registry with the exhaust duct E relatively sooner.

It has been found that the timing of the valve can be adjusted as described above without providing for adjustable timing of the rich inlet passage 123. The inlet passage 123, which provides for timed registry between the rich inlet duct R and the pre-combustion chamber 128, can be timed in accordance with average engine demand requirements through the establishment of a fixed opening size of the pre-combustion chamber 128. _ 24 _ The provision of the adjustable slide seals 138, however, provides for variation in the timing of the inlet and exhaust passages 122 and 124 to smooth out engine idle operation and reduce fuel consumption and emission outputs.

Thus, as the opposing seals 138 are moved into the restricting position during engine idle, both passages 122 and 124 are caused to open late (due to the restriction caused by the left-hand seal 138) near to top dead center and to close early (due to the restriction caused by the right-hand seal 138) near to bottom dead center, as is depicted in the graph Of Fig. 26.

As a result of the movement of the seals 138 into their restricting position, (1) valve overlap is virtually eliminated during idle and (2) the exhaust passage 124 does not move into registry with the exhaust duct E until the piston reaches virtually bottom dead center. The elimination of both valve overlap and the early opening of the exhaust port in response to a reduction in engine demand assures that combustion gases will not be introduced into the inlet passage 122 on the exhaust stroke and also assures that complete combustion takes place in the main combustion chamber 118 prior to the opening of the exhaust passage 124. Engine idle speed can therefore be reduced without the conventional attendant rough running, high fuel comsumption and high pollution output.

Referring especially to Fig. 24, the exhaust passage 124 is provided with an inner liner 145 formed from a heatresistant alloy, such as stainless steel which extends across each wall of the exhaust passage 124. Opposite ends of the inner liner 145 are bent outwardly and register with a sleeve extending around the valve body 120. The bends act as spacers to maintain the liner 145 spaced from each wall of the exhaust 25_ 430S© passage 124. A dead air space 146 between the wall of the exhaust passage and the liner 145 provides an insulating layer shielding the valve body from the exiting exhaust gases.

As the exhaust passage 124 rotates into registry with the main combustion chamber 118 and the exhaust duct E during an exhaust cycle of the piston 113, the hot, highly pressurized gases are released from the main combustion chamber 118 to flow over the surface of the liner 145. During engine operation, therefore, the liner 145 will be maintained at a red-hot temperature.

The dead air space 146 provides an insulating area between the liner 145 and each wall of the exhaust passage 124. The valve body 120 is thereby shielded from localized exhaust gas heat.

The valve body 120 is provided with cooling passages C which extend axially through the body 120 and are supplied with water from the engine cooling system. The provision of the liners 145 in the exhaust passage 124 permits the uniform cooling of the valve body 120 with cooling fluid, reducing localized hot spots in the valve body 120 around the area of each exhaust passage 124 therein.

Referring now to Figs. 27 and 28, an embodiment of an engine is shown, incorporating a charge admission control apparatus for a non-stratified charge engine 59. The engine 59 comprises piston 14' which the cylinders 12’ defined by a cylinder block 11'. A valve head 30' carries a rotary valve body 32' super-adjacent the cylinders 12' for rotation within the head 30' by a belt 62 drivingly connected to a crankshaft (not shown).

The valve body 32' comprises a light-weight, heat dissipative alloy frame 35' which defines inlet passages 36', exhaust passages 37' and axial cooling passages 38' similar in arrangement and function _ to those within the rotary valve body 32, previously described. As previously described, the exhaust passage includes a heat dissipating shield, such as the shield 51 of Figure 7.

Integral diaphragm gasket/seal 42’ are sandwiched 5 between the valve head 30' and the cylinder block 11' to effect sealing of the cylinders 12' in the manner previously described with respect to the gasket seals 42. Integral arcuate valve seals 44' within openings defined by a diaphragm gasket 43' may comprise either molded carbon or sintered metal and are lubricated in the same manner as the above described diaphragm gasket/seals 42. Each exhaust passage 37' is protected against high temperature exhaust gased by an inner liner 51' identical in structure and function to the liner 51 described above.

The engine is aspirated through a conventional carburetor (not shown) and manifolding 33' and 34' leading to respective passages 36' and 37'. The light-weight rotary valve head 30' and body 32', however, provide a greatly simplified valving structure. The engine 59 is extremely efficient, light-weight and has few moving parts. Furthermore, the valve body 32' is provided with a slide seal timing apparatus for the intake and exhaust, as previously described, to assure maximum engine performance.

Attention is directed to our Patent Specification. Nos. 43018, 43019 and 43021.

Claims (4)

1. A valve for a rotary valve internal combustion engine, said valve being of the type including a cylindrical valve body which is rotatable about its longitudinal axis within a cylinder head, and which is provided with at least one passage for communicating an engine cylinder with an exhaust manifold associated with the cylinder head, in Which said valve passage extends through the valve and opens into the peripheral surface of the valve at diametrically opposed positions, and a tubular heat shield is positioned within said exhaust passage and extends through said passage in spaced relationship therewith.

2. The valve according to Claim 1, in which the heat shield is formed of a heat resistant metal.

3. The valve according to Claim 1 or Claim 2, in which the tubular heat shield is retained within the exhaust passage by a tubular member surrounding and fast with the valve body, and which has apertures registering with the ends of the exhaust passage.

4. A valve for a rotary valve internal combustion engine, substantially as hereinbefore described with reference to and as illustrated in Figs. 7, 14, 15 and 16 of the accompanying drawings.